1. Field of the Invention
The present invention relates to a device package in which an electrode on a device, such as a semiconductor device or optical device, is connected to extra-device wiring or the like on an external wiring substrate through a metal wire, and to a method of manufacturing the device package.
2. Description of the Related Art
In general, an electrode on a semiconductor device or the like is electrically connected through a gold wire to extra-device wiring, such as a wiring pattern on an external wiring substrate, using a wire bonding apparatus (for example, see Japanese Laid-Open Patent Publication No. H05-90320). In such a conventional wire bonding technique, a ball formed at the tip end of the gold wire is first bonded to the electrode on the semiconductor device by applying a load, heat, or ultrasonic waves. Subsequently, the gold wire is guided by a capillary and moved to a position above the extra device wiring while forming a predetermined bending shape (loop shape) that is arched. Then, the gold wire is landed on the extra device wiring and bonded thereto by the load, heat or ultrasonic waves applied by the capillary. Thereafter, the capillary is upwardly withdrawn to complete the wire bonding.
However, the height of the top portion of the gold wire forming the bending shape that is arched is very high in the conventional wire bonding technique, so that the gold wire hinders the arrangement of other elements above the semiconductor device. Accordingly, the elements cannot be arranged close to the semiconductor device, thereby entailing a problem of lowering the degree of freedom in the layout of the elements.
Particularly, when an optical conductive path (fiber line or the like) transmitting an optical signal is arranged above the photo-detecting element in an optical device package or in an optical system, the shorter the distance between the photo-detecting element and the optical conductive path becomes, the more the performance or characteristic of the optical device package enhances. Therefore, a low height of the top portion of the gold wire connecting the photo-detecting element to the extra device wiring is greatly demanded in the optical device package in order to shorten the distance between the optical conductive path and the photo-detecting element as much as possible.